JP7458385B2 - Biogas plant for fermentation of organic substances and production of biogas - Google Patents

Description

The present invention relates to a biogas plant, preferably for the continuous fermentation of organic substances and the production of biogas.

In such commonly known biogas plants, a fermentation process is carried out in which organic substances as biomass, in particular agricultural and domestic organic residues, are gasified. A conventional biogas plant is provided with a pre-pit. This pre-pit is for collecting and processing organic materials for input into downstream fermenters where fermentation or gasification processes are carried out under aerobic or anaerobic conditions with microorganisms. Secondary fermentation usually takes place in downstream secondary fermentation tanks. This is then followed by a final storage tank for collecting fermentation residues. If necessary, such a biogas plant can also have further containers and tanks, for example for the collection of process water or non-fermentable pollutants. The biogas produced as biomethane in the fermenter is recovered and typically used to produce energy in a biogas plant, for example as heated gas or using a downstream gas-fired internal combustion engine with a generator. used to.

Known biogas plants are fixed plants, the tanks of which are either buried in the ground or designed as elevated tanks. Biomass for fermentation, e.g. corn, grass, stabilized manure, liquid fertilizer, fermentation sludge, slaughterhouse waste, domestic organic residues, etc., is transported in suitable vehicles to the stationary biogas plant and treated there. Ru.

Cities, especially large cities, have a considerable amount of waste, which is becoming increasingly difficult to dispose of in the most environmentally friendly way possible. Landfills disadvantageously require a large amount of space and also have unpleasant odors. Waste incineration facilities are not environmentally friendly as they emit pollutants. Household and municipal waste treatment companies collect so-called organic waste separately from normal residual waste, which is transported to stationary biogas plants for fermentation. Such biogas plants require relatively large areas and are often located far from cities due to the dense population of cities, often high land prices, and the potential for odor production. Can only be installed in remote locations. This can lead to undesirably long transport routes. Moreover, building new biogas plants in urban areas is usually no longer possible due to the lack of suitable land and often due to considerable resistance from citizens.

The above problems also affect coastal cities, especially in the southern latitudes, where garbage disposal has been known to be a major problem for many years. Due to the high summer temperatures, the treatment of organic waste is particularly important. The term organic waste is understood here to mean, in a very general way, any fermentable biomass that may be mixed with pollutants; for example, fermentable biomass generated in households and possibly including leftovers, commercial organic waste from hotels, waste from slaughterhouses, etc.

The aim of the invention is to develop a general biogas plant, environmentally friendly, economically effective and acceptable to citizens, for treating organic waste from coastal or near-coastal cities. It is in. Another object of the invention is to propose a method for retrofitting an oil tanker. Yet another object of the invention is to demonstrate a method of operating a biogas plant according to the invention.

The object relating to the development of a general biogas plant is achieved by the features of claim 1. Advantageous improvements are the subject of subclaims.

According to claim 1, a biogas plant is provided, preferably for the continuous fermentation of organic substances and for the production of biogas. The plant has a plurality of vessels and/or tanks, including at least one pre-pit, at least one fermenter downstream of the pre-pit, at least one secondary fermenter downstream of the fermenter, and/or or at least one final storage vessel downstream of the fermenter. According to the present invention, an entire functional biogas plant as a floating biogas plant is provided. In this biogas plant, the entire functional biogas plant as a floating biogas plant has at least one pre-pit, at least one fermenter, at least one secondary fermenter and/or at least one final tank. provided. The storage tank is part of a monolithic float or a cohesive float made up of multiple parts. According to the invention, it is further provided that the monolithic or multi-component float has its own drive and/or a device for coupling the towing body and/or a device for mooring in a port and/or for transportation. Having a device for coupling or mooring a ship and/or an anchoring device. Such a biogas plant is a floating biogas plant, in particular, to some port of a coastal city and/or to the waters of a coastal area (or a coastal area of a coastal city), preferably outside the 12 mile zone. The purpose is for continuous operation of gas plants. This operation includes, in particular, the collection by a transport vessel of organic waste generated in or provided at a port, preferably from land, or the collection of organic waste transported by a transport vessel to a waterside location. and preferably for the continuous fermentation of organic waste and preferably for the continuous production of biogas while in a port and/or in a body of water and/or during transit. This means that floating biogas plants are continuously moved to several ports in coastal cities or to locations in water bodies, especially anchorages, where they collect organic waste and carry out the fermentation process. By, it is meant to carry out preferably continuous fermentation and preferably continuous production of biogas during residence and/or during movement. A position in a body of water can be specified using coordinates, for example. If possible, floating biogas plants can also be anchored in the body of water. If this is not possible, a floating biogas plant can be temporarily retained in the body of water. For clarity, it is reiterated that a waterside location is a location in a body of water outside a port, preferably outside the 12 mile zone.

This allows organic waste from coastal cities, or nearby cities if necessary, to be processed in an environmentally and energy-efficient manner without the need to build and operate separate biogas plants in each of these cities, and without approval procedures or pre-emptive resistance from citizens. Furthermore, since the floating biogas plant can capture and collect organic waste at regular and relatively short time intervals, say one week, only a relatively small amount of organic waste needs to be collected and made processable for one week.

In the case of integrated floating bodies, the individual components of the floating biogas plant can be located on the floating body, integrated into the floating body, or both. In the case of continuous floating bodies with several parts, the individual components of the floating biogas plant are distributed over several floating body parts and, in particular, are arranged in each assigned floating body part and/or each integrated into a floating body.

Even more preferably, the floating biogas plant furthermore has at least one container and/or tank, in particular for process water and/or for pollutants.

The floating biogas plant can furthermore particularly preferably have a treatment device for organic waste. Organic waste can also contain pollutants, especially sand, plastic parts, paper/cardboard, etc. Preferably, the processing equipment is designed to be able to separate organic matter from organic waste as fermentable biomass, which is then fed to a fermentation process. The separated contaminants can be unloaded when docked in a port and/or loaded onto a transport vessel when docked at the water's edge. Alternatively or additionally, pollutants, especially plastic parts and/or paper/cardboard, can also be used at least partially for energy by combustion/gasification in a biogas plant. However, such processing equipment for separating pollutants and fermentable biomass can also be constructed and operated onshore in port areas, or can be decentralized, ensuring that only organic fermentable materials are present. Absorbed by a floating biogas plant.

In a particularly preferred embodiment, the floating biogas plant also has at least one biogas processing device for processing the produced biogas. This processing device is preferably formed by a device that liquefies biogas into liquefied natural gas (LNG) and a liquefied gas tank (LNG tank). Alternatively or additionally, the processing device can be formed by a device for producing CNG (Compressed Natural Gas) and a gas tank. In particular, CNG is generally compressed, for example to about 200-250 bar, so it can be formed by a high-pressure tank. Liquefied gas and/or CNG produced in a floating biogas plant can also be used, for example, as fuel for operating a biogas plant. In this case, it may be particularly advantageous for the propulsion drive of the floating biogas plant to have a gas engine that operates on a portion of the gas produced. As a result, the floating biogas plant becomes almost self-sufficient and independent of external energy supplies.

Alternatively or additionally, it may be provided that the processing device is in the form of a power plant, preferably a combined heat and power plant, capable of generating electrical power and/or heat. Such power plants may generate their own electricity to the extent necessary for the operation of the biogas plant, e.g. to operate the biogas plant units or auxiliary units such as pumps, heaters, stirrers, etc. can do. and/or can generate heat in the range necessary for operating a biogas plant. For example, heating a fermenter or heating tap water. In connection with such a power plant, a floating biogas plant can optionally have a drive with an electric machine, in particular an electric motor that can be operated with electricity generated via at least one storage battery. .

In particular, at least some vessels are arranged in a floating biogas plant, for example in order to homogeneously distribute organic substances within the fermenter sludge or to prevent solids from adhering to the vessel walls. In particular, at least one pre-pit, and/or at least one fermenter, and/or at least one secondary fermenter, and/or at least one final storage vessel, at least one stirring device, preferably height-adjustable. A stirring device and/or a stirring device with stirring blades is arranged.

Digestive fluids should preferably be pumped to onshore sewage treatment plants or discharged to sea. For example, the fermentation residue can be discharged into the sea, especially after solid-liquid separation. Separating contaminants such as sand and plastics before and after fermentation, using a solid-liquid separation system (separator), for example, can ensure that they do not enter the ocean. Only organic residues (fish food, so to speak) are discharged into the sea.

A monolithic floating body or a multi-part floating body can be designed, for example, as a raft-like pontoon structure to which containers, tanks and additional equipment of a biogas plant are attached. Such a pontoon structure can in particular be moved by being towed by a towing body. Such a relatively simple system is particularly suitable when the sea is calm and the travel route is between the port to be approached and the correspondingly smaller amount of organic waste in the smaller biogas system. ing.

On the other hand, in a much more functional and preferred embodiment of a floating biogas plant, the integral floating body is the hull of a navigable ship with a propulsion system, and this hull constitutes a floating biogas plant. elements, in particular one pre-pit in the hull, at least one fermenter using at least part of the outer shell wall, at least one secondary fermenter and/or at least one final storage container and possibly further containers and/or a tank. The superstructure of the ship is configured in particular in the form of an apparatus for liquefying biogas into liquefied gas, including liquefied gas tanks, and/or in the form of an apparatus for producing CNG (Compressed Natural Gas). It may also include a gas tank and/or be in the form of a power generation installation and/or be provided with at least one organic waste treatment device. There, for example, liquefied gas tanks can also be arranged in the hull.

Additionally, the hull can be insulated inside or outside to minimize heat loss from the hull.

As a very cost-effective solution for producing floating biogas plants, a conversion of a preferably double-walled oil tanker, which has been decommissioned from its oil transport role, in the form of a navigable vessel, in particular in the form of a steel vessel, is proposed, on which oil tanks, present at least in part as containers and/or tanks, in particular plant containers and/or process tanks, can be used. The double-walled construction can be advantageously used here for the insulation of the container and is also an essential safety element when used in biogas plants, since it prevents the escape of liquids, such as digestate, in case of leaks in the inner wall. Since the steel structure is already present, it is relatively simple and inexpensive to produce the vessels required for the fermentation process in the appropriate size by welding steel walls to this steel structure, if necessary.

A suitable spatial division for such a ship is obtained as follows. That is, from bow to stern, several, e.g., three, adjacent prepits separated by bulkheads and correspondingly several, e.g., three, adjoining fermenters or tanks and several, e.g., adjacent, pre-pits, separated by bulkheads. e.g. three secondary fermenters or tanks, some adjacent, e.g. three, possibly one more behind, final storage containers or tanks and preferably some, e.g. four, especially process water and contaminants. This results in further division into further containers or tanks for the substance and further marine propulsion applications. In the above structure, facilities for the treatment of organic waste, facilities for liquefying biogas, optionally facilities for combustion of pollutants, drying and pelletizing facilities, and liquid gas tanks can be arranged.

Furthermore, ships and pontoon structures similar to rafts may be mentioned, which are equipped with complete functional biogas plants.

Another method is to convert an abandoned oil tanker into a floating biogas plant as described above.

Furthermore, the above-mentioned method of operating a biogas plant may be mentioned. In this method, the biogas plant is made to successively call at various ports of coastal or near-coastal cities to receive organic waste and its organic matter generated and collected in those areas. And, after treatment, they are subjected to continuous fermentation and gasification processes during berthing at ports and during transit between ports. As an alternative to, or in combination with, the above, a floating biogas plant may also be temporarily berthed at a predetermined location in the coastal area of a coastal city, where it collects organic waste from transport vessels.

Needless to say, contaminants that may be generated in these processes can be carried back to shore as well. This is especially the case if gasification and/or incineration is not permitted and energy recovery and/or disposal of pollutants in territorial waters is also not permitted.

3 is a schematic vertical cross-sectional view of an oil tanker converted into a floating biogas plant, taken along line AA in FIG. 2. FIG. FIG. 2 is a schematic horizontal cross-sectional view of the oil tanker of FIG. 1 taken along line BB. 1 is a schematic diagram of a first operating mode of a floating biogas plant; FIG. FIG. 3 is a schematic diagram of a second operating mode of the floating biogas plant.

The invention will be further explained by an example using the drawings.

1 and 2 shows a floating biogas plant 1, here a double-walled oil tanker 2 modified for this purpose only by way of example. . In the hull 3 of the oil tanker 2, in order from the bow 4 to the stern 5, there are three adjacent pits 7a, 7b, 7c, each separated by a bulkhead 6, shown here by way of example only. and three mutually adjacent fermenters 8a, 8b, 8c, three mutually adjacent secondary fermenters 9a, 9b, 9c and three final storage containers juxtaposed as final storage tanks 10a, 10b, 10c. , four further tanks 11a, 11b, 11c, 11d, in particular for process water and pollutant collection, and a marine propulsion system 12 with a liquefied gas engine 13 are provided. Furthermore, a fourth final storage tank 10d is arranged behind the final storage tank 10b. Of course, different numbers of containers/tanks can also be provided.

The cross-sectional view in FIG. 1 also shows two height-adjustable agitators 14a, 14b in each tank 8, 9, 10, 11 (here, an agitator with one agitator blade is shown only as an example). These are not shown in FIG. 2 for the sake of clarity.

In FIG. 1, three (schematically shown) superstructures 15 are shown by way of example on the hull. This superstructure 15 can include devices 16a, 16b, not shown in detail, for the treatment of organic waste, incineration of pollutants, drying, pelletizing, etc., among others. Furthermore, a device 17 for liquefying the biogas and/or producing CNG (Compressed Natural Gas) is included in the superstructure 15. Here, the biogas is stored in a gas tank 18, a part of which is used for the gas engine 13 of the ship propulsion system 12, and other additional units are used as necessary. Alternatively, the device 17 may be a power generation installation, in particular a combined heat and power generation installation, or a gas engine 17 which is an electric machine.

In FIG. 3, a first mode of operation for using a floating biogas plant 1 for the treatment of organic waste is shown in a highly schematic and only exemplary manner. For this purpose, six coastal cities S1 to S6 are illustrated, spaced apart along the schematized coastline 19. The floating biogas plant 1 corresponding to the modified oil tanker 2 in Figures 1 and 2 is activated for these coastal cities S1 to S6 on a regular cycle, here once a week, and Organic waste is picked up from the intake 20 of the oil tanker 2 for one week and fed into the fermentation process. This fermentation process takes place continuously during the stay in the port and during the transfer between the ports of the coastal cities S1-S6. A suitable one-week cycle may begin with coastal city S1, enter coastal city S3 except next coastal city S2, and then enter coastal cities S5 and S6. On the return trip to the coastal city S1, ports are entered into the coastal cities S4 and S2 left behind on the outbound trip. As a result, one week of organic waste collection will be carried out for each of the coastal cities S1 to S6. The routes between coastal cities S1 to S6 are almost the same.

To estimate the size, assume that a total of 2 million people live in coastal cities S1-S6. A suitable size for the treatment of biowaste is obtained if each tank is approximately 10,000 m ³ , ie a total of 150,000 m ³ . For example, about 25,000 ^m3 with three pre-pit tanks 7a, 7b, 7c, 30,000 ^m3 with a plurality of e.g. three fermenters 8a, 8b, 8c, a plurality of e.g. three secondary fermenters 9a, 9b, 9c of 30,000 m ³ or optionally available a plurality ^, e.g. The appropriate size of the gas tank 18 for the liquefied gas tank is about 5,000 to 10,000 m ³ . In this example, the applicable area may be emptied about once a month. Similarly, this is also possible using CNG instead of liquefied gas, and the tank capacity needs to be adjusted accordingly. The size of the individual volumes is given here only as an example; for example, if there are 1 million inhabitants, this size can be halved.

In FIG. 3(b), an alternative embodiment of a floating biogas plant 1 by means of a converted oil tanker 2 is shown on a pontoon in which the functional units of a biogas plant with the necessary containers and additional equipment are placed. Shown with structure 21. It is moved by a tractor 22 to collect organic waste at the port facilities of coastal cities, for example coastal cities S1-S6. This alternative according to Fig. 3(b) is obviously only suitable for relatively simple situations, especially for relatively short routes in calm waters.

In FIG. 4 an alternative second mode of operation of the floating biogas plant 1 for the coastal cities S1 to S6 of FIG. 3 is shown. This can be combined, if necessary, with a first mode of operation in which the oil tanker 2 stays in port. As can be seen from FIG. 4, the floating biogas plant 1 is located here at a predetermined location 25 in front of the coastal cities S1 and S2, here temporarily close to the coast, for example outside the 12 mile zone 23. Existing. If possible, the floating biogas plant 1 is held in place by an anchoring device 24. The organic waste produced in the coastal cities S1 and/or S2 is transported from these coastal cities S1 and/or S2 by a transport vessel 26 to the floating biogas plant 1 for fermentation. The floating biogas plant 1 is then moved to a further predetermined temporary location 27, for example near the coast of coastal cities S3 and S4, and further to a location 28 near the coast of coastal cities S5 and S6. . At these locations, organic waste is transported from the mainland in a similar manner by transport vessels 26 to their respective temporary locations. The temporary location is preferably an anchorage.

Claims (9)

A biogas plant for the fermentation of organic matter and the production of biogas,
a plurality of containers and/or tanks forming at least one pre-pit (7 a, 7 b, 7 c ) , at least one fermenter (8 a, 8 b, 8 c ) arranged downstream of the pre-pit (7 a, 7 b, 7 c ), and at least one secondary fermenter (9 a, 9 b, 9 c ) and/or final storage vessel (10 a, 10 b, 10 c ) arranged downstream of the fermenter (8 a, 8 b, 8 c ),
said at least one pre-pit (7a , 7b, 7c ), at least one fermenter ( 8a, 8b, 8c ), at least one secondary fermenter ( 9a, 9b, 9c ) and at least one final storage vessel ( 10a, 10b, 10c ) being part of an integral floating body (3, 21);
The integrated floating body (3, 21) has its own propulsion system (12);
The integrated floating body is a hull (3) of a navigable ship equipped with a propulsion system (12), and at least one of the components of the floating biogas plant (1), namely at least one pre-pit (7a, 7b, 7c), at least one fermenter (8a, 8b, 8c), at least one secondary fermenter (9a, 9b, 9c), and a final storage vessel (10a, 10b, 10c), is arranged inside the hull (3) by partially utilizing the outer wall of the hull;
1. A biogas plant for the fermentation of organic matter and the production of biogas, characterized in that at least one biogas treatment device (17) in the form of an apparatus for liquefying biogas and/or in the form of an apparatus for producing CNG (Compressed Natural Gas) including a liquefied gas tank (18) is arranged on the superstructure (15) of a ship . Fermentation of organic substances according to claim 1, characterized in that the floating biogas plant (1) has a propulsion system (12) with a gas engine (13) operating with the gas generated. Biogas plant for the production of biogas. at least one pre-pit (7a, 7b, 7c), at least one fermenter (8a, 8b, 8c), at least one secondary fermenter (9a, 9b, 9c) and at least one final storage vessel ( 10a, 10b, 10c, 10d) for fermentation of organic substances and production of biogas according to claim 1 or 2, characterized in that at least one stirring device is arranged in at least one of (10a, 10b, 10c, 10d). biogas plant. The integral floating body is an insulated hull (3) of a navigable vessel equipped with a propulsion system (12);
at least one pre-pit (7a, 7b, 7c), at least one fermenter (8a, 8b, 8c), at least one secondary fermenter (9a, 9b, 9c) and at least one final storage vessel ( 10a, 10b, 10c) is arranged in a state where the outer wall of the hull of the hull (3) is partially used. biogas plants for the production of and for. Claim characterized in that further additional equipment is arranged in the superstructure (15) of the ship, in the form of a power generator and/or in the form of at least one treatment device (16) for biowaste. A biogas plant for fermentation of organic substances and production of biogas according to item 1. The biogas plant for fermentation of organic substances and production of biogas according to claim 1, characterized in that the ship is a modified oil tanker (2) that has finished its role of transporting oil. Between the bow (4) and the stern (5) of the hull (3) there are several adjacent pits (7a, 7b, 7c) separated by bulkheads and several adjacent fermenters or tanks ( 8a, 8b, 8c), several adjacent secondary fermenters or tanks (9a, 9b, 9c) and several juxtaposed final storage vessels or tanks (10a, 10b, 10c). is,
characterized in that in the superstructure (15) devices (16, 17) are arranged for the treatment of biowaste and /or for the incineration and/or drying and/or pelletization of pollutants. A biogas plant for fermentation of organic substances and production of biogas according to claim 1. 2. Biogas plant for the fermentation of organic matter and the production of biogas according to claim 1, characterized in that in the hull (3) several further containers or tanks (11a, 11b, 11c, 11d) are arranged together with an intermediate final storage vessel or tank (10d) and the propulsion system (12) of the vessel. A method for operating a floating biogas plant (1) according to claim 1, comprising :
Said floating biogas plant (1) is arranged to receive biowaste from at least different ports for a plurality of coastal cities (S1 to S6) and a plurality of locations different from said plurality of ports. The locations include temporarily designated waterfront locations (25 , 27, 28),
Biowastes are received by transport vessels (26) in ports and waterside locations (25, 27, 28) and fermented and The organic matter of biowaste is treated through a gasification process,
The fermentation residue collected in at least one final storage vessel (10a, 10b, 10c, 10d) can be pumped to a port sewage treatment facility and/or at least partially removed during transit between ports. A method for operating a floating biogas plant, characterized in that it can be discharged into the sea .

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